I was trying to make a new account using the same phone number that I used on my first one. I thought twitter said we can add up to 10 accounts using the same phone number? But why do I get errors that it is registered to another account and I can’t use it anymore to sign up for new accounts?
Do I need to wait for an hour or a day to be able to use the same phone number to sign up on a new account?

We’re unable to assist with general account issues here. If you already have a developer account, there should be no need to register additional accounts and also request developer access from those - if you require more apps, you should request this via the API policy support form.